Leopard and her new Doronbo Gang learn that they might be able to sneak into the Yatter Kingdom through an abandoned train tunnel. Making their way through the tunnel and arriving in the Yatter Kingdom, the gang come up against a pair of Yattermen and fight against them using a Forehead Flicking Mecha. However, they discover the Yattermen are actually robots, with an entire army showing up against them and destroying their mech. After barely escaping the Yatterman robots, Leopard and the others take shelter in an empty house to dry off. Just then, a young girl shows up at the house, claiming Leopard to be her angel.